Rear Admiral John Kirby described the close encounter, which took place in international airspace near Japan, as "pretty aggressive, very unprofessional and unsafe".

Pictures released by the US Department of Defense showed the plane was close enough to see into the cockpit.

Adm Kirby said it was the fourth incident since March of "close intercepts" involving Chinese jets.

The latest encounter happened on August 19 about 135 miles (215km) east of China's Hainan Island.

Image:The US says its P-8 was conducting routine surveillance

The US said its plane had been conducting routine surveillance.

But in a statement, the Chinese said: "The US side's criticism of China is totally groundless."

Video:Chinese Jet 'Rolled Over' US Plane

Beijing maintained the jet had kept a safe distance from the American aircraft, and held the US responsible.

It said: "The US's large-scale and highly frequent close-in reconnaissance against China is the root cause of accidents endangering the sea and air military security between China and the United States."

There are continuing tensions between the two countries amid competing territorial claims between China and its neighbours, some of which are US allies.

In 2001, a Chinese jet collided with a US Navy surveillance aircraft off Hainan Island, killing the Chinese pilot and forcing the Navy plane to make an emergency landing.

The 24 members of US air crew were held for 11 days until America apologised for the incident, which soured relations between Washington and Beijing.